Chemical Mechanical Planarization of Films Comprising Elemental Silicon

ABSTRACT

Chemical Mechanical Planarization (CMP) polishing compositions comprising abrasive particles and additives to boost removal rates of films comprising elemental silicon such as poly-silicon and Silicon-Germanium.

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application is a non-provisional of U.S. provisional patentapplication Ser. No. 62/464,680, filed on Feb. 28, 2017, which isincorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION

The present invention relates to chemical mechanical planarization(“CMP”) polishing compositions (CMP slurries, CMP composition or CMPcompositions are used interchangeably) used in the production of asemiconductor device, and polishing methods for carrying out chemicalmechanical planarization. In particular, it relates to polishingcompositions for polishing of films comprising elemental forms ofsilicon such as poly-Si, amorphous Si or Si—Ge.

Si containing films have been used in semiconductor industry for a longtime. There have many approaches taken to polish Si containing films athigh removal rates.

U.S. Pat. No. 3,429,080 discloses using oxidizing agents to boostremoval rates of crystalline Si films. US2013109182 disclosecompositions comprising diquaternary cations for polishing poly-Si filmsat high rates relative to silicon nitride. U.S. Pat. No. 6,533,832describes increased selectivity to poly-Si polishing using alcohol aminecompounds. U.S. Pat. No. 7,585,340 discloses compositions comprisingpolyetheramine compounds that yield high poly Si removal rates relativeto other films.

Despite these polishing compositions and methods, there remains a needin the art for polishing compositions and methods that can provide highremoval rates for films comprising elemental silicon and a controlledselectivity of removal rates between films comprising elemental siliconand other films such as silicon oxide and silicon nitride. Thecompositions and methods of this invention provides these inventivefeatures as it will be apparent from the description of the inventionprovided herein.

BRIEF SUMMARY OF THE INVENTION

Described herein are silicon containing material CMP polishingcompositions, methods and systems that satisfy the need.

In one embodiment, described herein is a polishing compositioncomprising abrasive particles, a liquid carrier and a compound to boostthe removal rates of films comprising elemental silicon, which isselected from a group consisting of (i) heterocycle carbon compoundcomprising sulfur or nitrogen or both sulfur and nitrogen as heteroatomsand a carbonyl group attached to the ring structure (ii) Heterocyclecarbon compound comprising sulfur or nitrogen or both sulfur andnitrogen as heteroatoms (iii) Aldehyde or ketone compound.

In a preferred embodiment, the compound to boost the removal rates offilms comprising elemental silicon is a heterocyclic carbon compoundcomprising both sulfur and nitrogen heteroatoms along with a carbonylgroup attached to the carbon ring.

In a further preferred embodiment, the compound to boost the removalrates of films comprising elemental silicon is a isothiazolinonecompound. Examples of chemical isothiazolinone compounds include but notlimited to methylisothiazolinone (MIT), chloromethylisothiazolinone(OMIT), benzisothiazolinone (BIT), octylisothiazolinone (OIT),dichlorooctylisothiazolinone (DCOIT) and butylbenzisothiazolinone(BBIT).

In a further embodiment, the polishing composition comprises one or moreabrasive particle selected from a group consisting of silicon oxide,cerium oxide or a composite particle comprising silicon oxide and ceriumoxide; and methylisothiazolinone as the compound to boost removal ratesof films comprising elemental silicon.

In a further embodiment, the polishing composition comprises one or moreabrasive particle selected from a group consisting of silicon oxide,cerium oxide or a composite particle comprising silicon oxide and ceriumoxide; methylisothiazolinone as the compound to boost removal rates offilms comprising elemental silicon; and an additive to suppress removalrate of silicon nitride films.

In a further embodiment, the polishing composition comprises one or moreabrasive particle selected from a group consisting of silicon oxide,cerium oxide or a composite particle comprising silicon oxide and ceriumoxide; methylisothiazolinone as the compound to boost removal rates offilms comprising elemental silicon; and a polymer or co-polymercontaining acrylic acid group.

In a further embodiment, the polishing composition comprises a ceriumoxide containing abrasive, a silica abrasive, methylisothiazolinone asthe compound to boost removal rates of films comprising elementalsilicon; and a polymer or co-polymer containing acrylic acid group as anadditive to suppress removal rate of silicon nitride films.

Polishing compositions may also comprise other types of additives suchas surfactants, dispersants, corrosion inhibitors, biocides, pHadjusting agents, pH buffering compounds, etc.

Polishing compositions of this invention may comprise abrasive particlesin the concentration range of 0.01 wt. % to about 15 wt. %, or morepreferably between 0.1 wt. % to about 5 wt. %, or most preferablybetween 0.2 wt. % to about 3 wt. %.

Compound to boost removal rate of films comprising elemental silicon maybe present in the range of 0.0001 wt. % to 1 wt. %, or more preferablybetween 0.001 wt. % to 0.5 wt. %, or most preferably between 0.01 wt. %and 0.2 wt. %.

Typically, pH of the polishing composition is between 1 and 13,preferably between 2 and 12 and more preferably between 3 and 11.

The present invention provides a polishing composition comprising:

-   -   abrasive particles ranging from 0.01 wt. % to 15 wt. %;    -   a compound to enhance removal rate of films comprising elemental        silicon ranging from 0.001 wt. % to 0.5 wt. %; and    -   liquid carrier; and    -   pH of the polishing composition is between 2 and 12;    -   wherein    -   one or more kinds of abrasive is selected from the group        consisting of fumed silica, colloidal silica, fumed alumina,        colloidal alumina, cerium oxide, ceria-silica composite        particles, titanium dioxide, zirconium oxide, polystyrene,        polymethyl methacrylate, mica, hydrated aluminum silicate, and        mixtures thereof; and    -   the compound to enhance removal rate of films comprising        elemental silicon is selected from a group consisting of (i)        heterocycle carbon compound comprising sulfur or nitrogen or        both sulfur and nitrogen as heteroatoms and a carbonyl group        attached to the ring structure; (ii) heterocycle carbon compound        comprising sulfur or nitrogen or both sulfur and nitrogen as        heteroatoms; (iii) an aldehyde or a ketone compound; and        combinations thereof.

The present invention provides a polishing method for chemicalmechanical planarization of a semiconductor substrate comprising atleast one surface containing elemental silicon, comprising the steps of:

-   -   contacting the at least one surface containing elemental silicon        with a polishing pad;    -   delivering a polishing composition to the at least one surface        containing elemental silicon;    -   wherein the polishing composition comprising:        -   abrasive particles ranging from 0.01 wt. % to 15 wt. %;        -   a compound to enhance removal rate of films comprising            elemental silicon ranging from 0.001 wt. % to 0.5 wt. %; and        -   liquid carrier; and        -   pH of the polishing composition is between 2 and 12;        -   wherein        -   one or more kinds of abrasive is selected from the group            consisting of fumed silica, colloidal silica, fumed alumina,            colloidal alumina, cerium oxide, ceria-silica composite            particles, titanium dioxide, zirconium oxide, polystyrene,            polymethyl methacrylate, mica, hydrated aluminum silicate,            and mixtures thereof; and the compound to enhance removal            rate of films comprising elemental silicon is selected from            a group consisting of isothiazolinone and derivatives,            thiazolinone and derivatives, imidazolidine and derivatives,            pyrozolidine and derivatives, imidazole and derivatives,            pyrazole and derivatives, thiazole and derivatives,            isothiazole and derivatives, thiazolidine and derivatives,            isothiazolidine and derivatives, dithiolane and derivatives,            triazole and derivatives, tetrazole and derivatives,            thiadiazole and derivatives, and combinations thereof;            acetone, benzophenone, acetophenone, acetylacetone, butanol,            3-hydroxybutanal, p-nitrobenzenzaaldehyde, cinnamaldehyde,            vanillin, and combinations thereof;    -   and    -   polishing the at least one surface containing elemental silicon        with the polishing composition.

The present invention provides a polishing system for chemicalmechanical planarization a semiconductor substrate comprising at leastone surface containing elemental silicon, comprising:

-   -   the semiconductor substrate;    -   a polishing pad; and    -   the polishing composition comprising:        -   abrasive particles ranging from 0.01 wt. % to 15 wt. %;        -   a compound to enhance removal rate of films comprising            elemental silicon ranging from 0.001 wt. % to 0.5 wt. %; and        -   liquid carrier; and        -   pH of the polishing composition is between 2 and 12;        -   wherein        -   the abrasive is selected from the group consisting of fumed            silica, colloidal silica, fumed alumina, colloidal alumina,            cerium oxide, ceria-silica composite particles, titanium            dioxide, zirconium oxide, polystyrene, polymethyl            methacrylate, mica, hydrated aluminum silicate, and mixtures            thereof; and        -   the compound to enhance removal rate of films comprising            elemental silicon is selected from a group consisting of            isothiazolinone and derivatives, thiazolinone and            derivatives, imidazolidine and derivatives, pyrozolidine and            derivatives, imidazole and derivatives, pyrazole and            derivatives, thiazole and derivatives, isothiazole and            derivatives, thiazolidine and derivatives, isothiazolidine            and derivatives, dithiolane and derivatives, triazole and            derivatives, tetrazole and derivatives, thiadiazole and            derivatives, and combinations thereof; acetone,            benzophenone, acetophenone, acetylacetone, butanol,            3-hydroxybutanal, p-nitrobenzenzaaldehyde, cinnamaldehyde,            vanillin, and combinations thereof;    -   wherein the semiconductor substrate is in contact with the        polishing composition and the pad.

The compound to enhance removal rate of films comprises elementalsilicon can be selected from a group consisting of (i) isothiazolinoneand derivative selected from the group consisting ofmethylisothiazolinone (MIT), chloromethylisothiazolinone (OMIT),benzisothiazolinone (BIT), octylisothiazolinone (OIT),dichlorooctylisothiazolinone (DCOIT), butylbenzisothiazolinone (BBIT),and combinations thereof; and (ii) thiazolinone and derivative selectedfrom the group consisting of 2-Benzothiazol-1,1,3-trione (Saccharin),N-methyl 2-Benzothiazolinone, thiazolinone, and combinations thereof;and combinations thereof.

The semiconductor substrate further comprises at least one surfacecontaining silicon oxide, silicon nitride or combinations thereof; andthe polishing composition further comprises from 0.1 ppm to 0.5 wt. % ofan additive having a functional group selected from the group consistingof organic carboxylic acids and salts thereof, amino acids and saltsthereof, amidocarboxylic acids and salts thereof, N-acylamino acids andsalts thereof, organic sulfonic acids and salts thereof; organicphosphonic acids and salts thereof; polymeric carboxylic acids and saltsthereof; polymeric sulfonic acids and salts thereof; polymericphosphonic acids and salts thereof; arylamines, aminoalcohols, aliphaticamines, heterocyclic amines, hydroxamic acids, substituted phenols,sulfonamides, thiols, polyols having hydroxyl groups, and combinationsthereof; or combinations of (i) and (ii);

The disclosed method and the system can provide a tunable removal rateselectivity between elemental silicon and silicon oxide or siliconnitride between 0.1 to 110.

DETAILED DESCRIPTION OF THE INVENTION

Polishing compositions of this invention are useful for polishing filmscomprising elemental silicon at high removal rates.

Films comprising elemental silicon comprise various types of filmscontaining silicon in which chemical bonding of silicon with otherelements is substantially absent. Films comprising elemental siliconinclude various crystalline forms of silicon such as polycrystalline(also referred to as poly-Si), amorphous silicon (referred to as a-Si)or single crystal.

Films comprising elemental silicon may also comprise various doping oralloying additives. Examples of doping or alloying additives include butnot limited to germanium, phosphorous, boron, aluminum, nitrogen,gallium, indium, arsenic, antimony, lithium, xenon, gold, platinum. Therelative ratio of atoms between the doping or alloying additives and Isilicon in the film could range from 1E-10 to 99.99999.

In one embodiment, polishing compositions are used to polish two or morefilms simultaneously wherein at least one of the films compriseselemental silicon and at least one other film comprises a compound ofsilicon.

Film comprising compound of silicon may comprise various types filmsincluding but not limited to silicon oxide, silicon nitride, siliconcarbide, silicon oxy-carbide, silicon oxy-nitride. Examples of siliconoxide films include but not limited to thermal oxide, Tetra Ethyl OrthoSilicate (TEOS), High Density Plasma (HDP) oxide, High Aspect RatioProcess (HARP) films, fluorinated oxide films, doped oxide films,organosilicate glass (OSG) low-K dielectric films, Spin-On Glass (SOG),flowable Chemical Vapor Deposited (CVD) films, optical glass, displayglass.

Polishing compositions of this invention can achieve a range of removalrate selectivity between the films comprising elemental silicon andfilms comprising compounds of silicon.

In some embodiments, removal rates of films comprising elemental siliconcan be very high compared to films comprising compounds of silicon. Forexample, polishing composition can polish poly-Si at very high ratescompared to silicon oxide and/or silicon nitride films with removal rateselectivity greater than 20.

In some other embodiments, polishing compositions can polish bothpoly-Si and silicon oxide at very high rates, with removal rateselectivity between poly-Si and silicon oxide less than 5.

In certain embodiments, all the three films poly-Si, silicon oxide andsilicon nitride are all polished at comparable removal rates, whereinthe ratio of removal rates between any two films is less than 5.

In certain embodiments, poly-Si films are polished at removal rateswhich are 1.5 times or more preferably more than 2 times silicon oxideremoval rate, while the removal rate selectivity between poly-Si and SiNis greater than 25.

In some embodiments, polishing compositions of this invention may beused to polish films comprising elemental silicon at removal ratesgreater than 500 Å/min, or more preferably more than 1000 Å/min, or mostpreferably more than 1500 Å/min. In some embodiments, removal rates offilms comprising elemental silicon is greater than 1000 Å/min, while thesilicon oxide removal rate is less than 50 Å/min. In some embodiments,removal rates of films comprising elemental silicon is greater than 1000Å/min, while the silicon oxide removal rate is greater than 500 Å/min.

These compositions can be used in a variety of applications includingbut not limited to Shallow Trench Isolation (STI), Inter LayerDielectric (ILD) polish, Inter Metal Dielectric (IMD) polish, throughsilicon via (TSV) polish and bare wafer polishing.

In one embodiment, described herein is a polishing compositioncomprising abrasive particles, a liquid carrier and a compound to boostthe removal rates of films comprising elemental silicon, which isselected from a group consisting of (i) heterocycle carbon compoundcomprising sulfur or nitrogen or both sulfur and nitrogen as heteroatomsand a carbonyl group attached to the ring structure (ii) heterocyclecarbon compound comprising sulfur or nitrogen or both sulfur andnitrogen as heteroatoms (iii) aldehyde or a ketone compound.

Heterocyclic carbon compound can be defined as a cyclic compound or aring structure with at least two different elements including carbon.Heteroatoms may comprise one or more atoms selected from carbon,nitrogen and oxygen. Heterocyclic ring may comprise 3 to 7 atoms asmembers. Heterocyclic ring may also be fused with benzene rings.

Examples of heterocycle carbon compounds having both carbon and nitrogenand a carbonyl group attached to the ring include but not limited toisothiazolinone, thiazolinone and their derivative compounds.

Examples of chemical isothiazolinone compounds include but not limitedto methylisothiazolinone (MIT), chloromethylisothiazolinone (OMIT),benzisothiazolinone (BIT), octylisothiazolinone (OIT),dichlorooctylisothiazolinone (DCOIT) and butylbenzisothiazolinone(BBIT).

Examples of thiazolinone compounds include but not limited to2-Benzothiazol-1,1,3-trione (Saccharin), N-methyl 2-Benzothiazolinoneand thiazolinone.

Examples of heterocycle carbon compounds comprising sulfur or nitrogenor both as heteroatoms include but not limited to imidazolidine,pyrozolidine, imidazole, pyrazole, thiazole, isothiazole, thiazolidine,isothiazolidine, dithiolane, triazole, tetrazole, thiadiazole, andderivatives thereof.

Examples of an aldehyde or a ketone compound include but not limited toacetone, benzophenone, acetophenone, acetylacetone, butanol,3-hydroxybutanal, p-nitrobenzenzaaldehyde, cinnamaldehyde, vanillin.

Compound to boost removal rate of films comprising elemental Si may bepresent in the CMP composition in the range of 0.0001 wt. % to 1 wt. %,or more preferably between 0.001 wt. % to 0.5 wt. %, or most preferablybetween 0.01 wt. % and 0.2 wt. %.

CMP compositions of this invention comprise abrasive particles.

Abrasive particles can be selected from a wide range of particles, butnot limited to fumed silica, colloidal silica, silica doped withaluminum, fumed alumina, colloidal alumina, cerium oxide, ceria-silicacomposite particles, titanium dioxide, zirconium oxide, polystyrene,polymethyl methacrylate, mica, hydrated aluminum silicate, and mixturesthereof.

Polishing compositions comprising silica or alumina particles may bepreferred for polishing films comprising elemental silicon at higherremoval rate selectivity relative to silicon oxide films.

Polishing compositions comprising silica or alumina particles forexample may be used to polish wafers when desired removal rateselectivity between films comprising elemental silicon and silicon oxidefilms is greater than 20, or more preferably greater than 30 or mostpreferably more than 50.

Polishing compositions comprising cerium oxide or ceria-silica compositeparticles may be more suitable for applications which require highremoval rates for both elemental silicon films and silicon oxide films.

Polishing compositions comprising cerium oxide or ceria-silica compositeparticles for example may be used to polish wafers when desired removalrate selectivity between films comprising elemental silicon and siliconoxide films is less than 10, or more preferably less than 5 or mostpreferably less than 2.

The mean particle size of abrasive particles can be measured by asuitable technique such as dynamic light scattering.

The mean particle size of silica and alumina particles can be between 10nm and 500 nm, more preferably between 20 nm and 150 nm, most preferablybetween 30 and 80 nm.

The mean particle size ceria or ceria-silica composite particles can bebetween 10 nm and 5000 nm, or more preferably between 50 nm and 300 nmand most preferably between 75 nm and 200 nm.

Ceria particles may be manufactured by any suitable techniques includingcalcination-milling or colloid formation through liquid processing.Ceria particles may be single crystalline or polycrystalline. In certaincases the surface may also be in hydroxylated form.

In some embodiments, composite particles, such as ceria-silica compositeparticles with ceria coated on the surface of silica particle core maybe preferred.

Ceria coating on silica core may be in the form of continuous shell likestructure or in the form of discreet ceria nano particles on the surfaceof silica particles.

In some embodiments, silica core particles are amorphous; and the ceriananoparticles are singly crystalline.

In some preferred embodiments, the ceria coated silica particles wouldcomprise a silica core with mean particle size in the range of 50 to 200nm, decorated with ceria nano particles of size as measured bytransmission electron microscope imaging is between 1 nm and 30 nm, ormore preferably between 10 nm and 20 nm.

In certain embodiments the ceria nano particles covering the silica coreparticle may have a partial silica coating on the surface.

Ceria-silica composite particles can be manufactured by the methodsdescribed by any suitable method. A method described in WO2016159167 maybe especially suitable for manufacturing ceria coated silica particlesfor improved performance.

Another aspect of the present invention, involves using of ceria coatedsilica particles that do not disintegrate under polishing forces. It ishypothesized that if the particles do not breakdown under the action ofpolishing forces (i.e. disintegrative forces) and keep thecharacteristic of original particle size, then the removal rate wouldremain high. If the particles on the other hand disintegrates underpolishing forces, the removal rate would decrease owing to effectivelysmaller abrasive particle size. Breaking of the particles may also yieldirregular shaped particles which may have undesirable effect onscratching defects. Particle stability under disintegrative forces canalso be determined by subjecting the composition to the ultrasonicationtreatment for half an hour and measuring the changes in sizedistribution.

Preferred conditions for ultrasonication treatment are ½ hour immersionin bath with 42 KHZ frequency at 100 W output. Particle sizedistribution can be measured by using any suitable technique such asDisc Centrifuge (DC) method or Dynamic Light Scattering (DLS). Changesin size distribution can be characterized in terms of changes in meanparticle size or D50 (50% particles below this size) or D99 (99%particles below this size) or any similar parameters.

Preferably the changes in particle size distribution of ceria coatedsilica particles after ultrasonication treatment is less than 10%, morepreferably less than 5% or most preferably less than 2%; by using forexample DC and mean particle size, D50, D75 and/or D99. Using suchstable particles in CMP slurry compositions would allow more effectiveutilization of polishing forces for film material removal and would alsoprevent generation of any irregular shapes that would contribute toscratching defects

Since advanced CMP applications require extremely low levels metals suchas sodium on the dielectric surface after polishing, it is desired tohave very low trace metals, especially sodium in the polishingcompositions. In certain preferred embodiments the compositions compriseabrasive particles that have less than 5 ppm, more preferably less than1 ppm most preferably less than 0.5 ppm of sodium impurity levels foreach percent of particles in the compositions by weight.

Polishing compositions of this invention may comprise abrasive particlesin the concentration range of 0.001 wt. % to about 15 wt. %, or morepreferably between 0.01 wt. % to about 5 wt. %, or most preferablybetween 0.05 wt. % to about 3 wt. %.

In certain embodiments, both elemental Si containing films and siliconoxide films need to be polished at high rates (>500 Å/min at 4 psidownforce) while at the same time remove elemental silicon films atrates which are preferably 1.5 times or more preferably more than 2times faster than the removal rate of silicon oxide films.

Polishing compositions for this embodiment comprise at least two typesof abrasive particles, wherein first particle is a cerium oxidecontaining abrasive particles and second particle is silica; a removalrate booster for elemental silicon films comprising isothiazolinone andthiazolinone compounds. Concentration of cerium oxide containingabrasive particles may preferably between 0.01 to 5 wt. %, or morepreferably between 0.02 and 1 wt. %. Concentration of silica particlesis preferably between 0.01 and 5 wt. % or more preferably between 0.1and 2 wt. %.

Some other embodiments may additionally require removal rates of siliconnitride films may be much lower compared to elemental silicon andsilicon oxide films.

Polishing compositions for these embodiments would additionally comprisecompounds to suppress silicon nitride removal rate.

These additive may include, but is not limited to compounds having afunctional group selected from the group consisting of organiccarboxylic acids, amino acids, amidocarboxylic acids, N-acylamino acids,and their salts thereof; organic sulfonic acids and salts thereof;organic phosphonic acids and salts thereof; polymeric carboxylic acidsand salts thereof; polymeric sulfonic acids and salts thereof; polymericphosphonic acids and salts thereof; arylamines, aminoalcohols, aliphaticamines, heterocyclic amines, hydroxamic acids, substituted phenols,sulfonamides, thiols, polyols having hydroxyl groups, and combinationsthereof. Preferred additive are polymers or copolymers comprisingacrylic acid groups. A preferred polymer is ammonium polyacrylate.

In yet another embodiment, elemental silicon films can be polished athigh rates along with metallic films (for example copper, tungsten) asis required for polishing applications such as through-Via-Silicon (TSV)CMP.

Liquid carrier in the CMP composition may comprise water.

Polishing compositions may also comprise other types of chemicaladditives for additional purposes such as boosting oxide rates, reducingsilicon nitride rates, boosting removal rate of metallic films,corrosion inhibitors for metallic films, etc.

These additive may include, but is not limited to compounds having afunctional group selected from the group consisting of organiccarboxylic acids, amino acids, amidocarboxylic acids, N-acylamino acids,and their salts thereof; organic sulfonic acids and salts thereof;organic phosphonic acids and salts thereof; polymeric carboxylic acidsand salts thereof; polymeric sulfonic acids and salts thereof; polymericphosphonic acids and salts thereof; arylamines, aminoalcohols, aliphaticamines, heterocyclic amines, hydroxamic acids, substituted phenols,sulfonamides, thiols, polyols having hydroxyl groups, triazolecompounds, and combinations thereof.

Preferred additive are polymers or copolymers comprising acrylic acidgroups. A preferred polymer is ammonium polyacrylate. Molecular weightrange of polyacrylic acid or its salt may range from 1,00 to 5,000,000or preferably between 500 to 100,000 or most preferably between 1,000and 20,000.

The amount of chemical additive ranges from about 0.1 ppm to 0.5 wt. %relative to the total weight of the barrier CMP composition. Thepreferred range is from about 200 ppm to 0.3% and more preferred rangeis from about 500 ppm to 0.15 wt. %.

Polishing compositions may also comprise pH adjusting agents or pHbuffering additives or both in order to achieve and maintain the pH ofthe composition.

The pH adjusting agent includes, but is not limited to, sodiumhydroxide, cesium hydroxide, potassium hydroxide, cesium hydroxide,ammonium hydroxide, quaternary organic ammonium hydroxide (e.g.tetramethylammonium hydroxide) and mixtures thereof.

The pH buffering agent may comprise a salt of an organic or inorganicacid with a base. Suitable pH buffering agents include but not limitedto salts of polyacrylic acid, citric acid, acetic acid, carbonic acid,bicine, tricine, Tris, 4-(2-hydroxyethyl)-1-piperazineethanesulfonicacid, N-cyclohexyl-3-aminopropanesulfonic acid,3-(N-morpholino)propanesulfonic acid, andpiperazine-N,N-bis(2-ethanesulfonic acid).

The amount of pH-adjusting agent or pH buffering agent or both rangesfrom about 0.0001 wt. % to about 5 wt. % relative to the total weight ofthe CMP composition. The preferred range is from about 0.0005 wt. % toabout 1 wt. %, and more preferred range is from about 0.0005 wt. % toabout 0.5 wt. %

Typically, pH of the polishing composition is between 1 and 13,preferably between 2 and 12 and more preferably between 3 and 10.Polishing compositions with higher pH would yield higher poly-Si rate.However, at higher pH especially beyond 8, removal rate of silicon oxideor silicon nitride films may also increase. For certain applicationswhere it is necessary to have very low silicon oxide or silicon nitrideremoval rate, preferred pH range may be between 4 to 10.

The CMP composition may comprise a surfactant.

The surfactant includes, but is not limited to, a). Non-ionic surfacewetting agents; b). Anionic surface wetting agents; c). Cationic surfacewetting agents; d). ampholytic surface wetting agents; and mixturesthereof.

Non-ionic surfactants may be chosen from a range of chemical typesincluding but not limited to long chain alcohols, ethoxylated alcohols,ethoxylated acetylenic diol surfactants, polyethylene glycol alkylethers, proplylene glycol alkyl ethers, glucoside alkyl ethers,polyethylene glycol octylphenyl ethers, polyethylene glycol alkylpgenylethers, glycerol alkyl esters, polyoxyethylene glycol sorbiton alkylesters, sorbiton alkyl esters, cocamide monoethanol amine, cocamidediethanol amine dodecyl dimethylamine oxide, block copolymers ofpolyethylene glycol and polypropylene glycol, polyethoxylated tallowamines, fluorosurfactants. The molecular weight of surfactants may rangefrom several hundreds to over 1 million. The viscosities of thesematerials also possess a very broad distribution.

Anionic surfactants include, but are not limited to salts with suitablehydrophobic tails, such as alkyl carboxylate, alkyl polyacrylic salt,alkyl sulfate, alkyl phosphate, alkyl bicarboxylate, alkyl bisulfate,alkyl biphosphate, such as alkoxy carboxylate, alkoxy sulfate, alkoxyphosphate, alkoxy bicarboxylate, alkoxy bisulfate, alkoxy biphosphate,such as substituted aryl carboxylate, substituted aryl sulfate,substituted aryl phosphate, substituted aryl bicarboxylate, substitutedaryl bisulfate, substituted aryl biphosphate etc. The counter ions forthis type of surface wetting agents include, but are not limited topotassium, ammonium and other positive ions. The molecular weights ofthese anionic surface wetting agents range from several hundred toseveral hundred-thousands.

Cationic surface wetting agents possess the positive net charge on majorpart of molecular frame. Cationic surfactants are typically halides ofmolecules comprising hydrophobic chain and cationic charge centers suchas amines, quaternary ammonium, benzyalkonium and alkylpyridinium ions.

Yet, in another aspect, the surfactant can be an ampholytic surfacewetting agents possess both positive (cationic) and negative (anionic)charges on the main molecular chains and with their relative counterions. The cationic part is based on primary, secondary, or tertiaryamines or quaternary ammonium cations. The anionic part can be morevariable and include sulfonates, as in the sultaines CHAPS(3-[(3-Cholamidopropyl)dimethylammonio]-1-propanesulfonate) andcocamidopropyl hydroxysultaine. Betaines such as cocamidopropyl betainehave a carboxylate with the ammonium. Some of the ampholytic surfactantsmay have a phosphate anion with an amine or ammonium, such as thephospholipids phosphatidylserine, phosphatidylethanolamine,phosphatidylcholine, and sphingomyelins.

Examples of surfactants also include, but are not limited to, dodecylsulfate sodium salt, sodium lauryl sulfate, dodecyl sulfate ammoniumsalt, secondary alkane sulfonates, alcohol ethoxylate, acetylenicsurfactant, and any combination thereof.

Examples of suitable commercially available surfactants include TRITON™,Tergitol™, DOWFAX™ family of surfactants manufactured by Dow Chemicalsand various surfactants in SURFYNOL™, DYNOL™, Zetasperse™, Nonidet™, andTornadol™ surfactant families, manufactured by Air Products andChemicals.

Suitable surfactants may also include polymers comprising ethylene oxide(EO) and propylene oxide (PO) groups. An example of EO-PO polymer isTetronic™ 90R4 from BASF Chemicals.

Other surfactants that have functions of dispersing agents and/orwetting agents include, but are not limited to, polymeric compoundswhich may have anionic or cationic or nonionic or zwitterioniccharacteristics. Examples are polymers/copolymers containing functionalgroups such as acrylic acid, maleic acid, sulfonic acid, vinyl acid,ethylene oxide, etc.

The amount of surfactant ranges from about 0.0001 wt. % to about 10 wt.% relative to the total weight of the CMP composition. The preferredrange is from about 0.001 wt. % to about 1 wt. %, and more preferredrange is from about 0.005 wt. % to about 0.1 wt. %.

The CMP composition may comprise biological growth inhibitors orpreservatives to prevent bacterial and fungal growth during storage.

The biological growth inhibitors include, but are not limited to,tetramethylammonium chloride, tetraethylammonium chloride,tetrapropylammonium chloride, alkylbenzyldimethylammonium chloride,isothiazolin compounds and alkylbenzyldimethylammonium hydroxide,wherein the alkyl chain ranges from 1 to about 20 carbon atoms, sodiumchlorite, and sodium hypochlorite.

Some of the commercially available preservatives include KATHON™ andNEOLENE™ product families from Dow Chemicals, and Preventol™ family fromLanxess. More are disclosed in U.S. Pat. No. 5,230,833 (Romberger etal.) and US Patent Application No. US 20020025762. The contents of whichare hereby incorporated by reference as if set forth in theirentireties.

In certain embodiments, the slurry can be manufactured in a concentratedform and be diluted at point of use with water. In some otherembodiments, slurry can be manufactured in two or more components, thatmay be mixed at point of use along with optional dilution with water inorder to overcome potential issues such as particle stability inslurries, cost of shipping etc.

WORKING EXAMPLES

Polishing Pad IC1010 pad, supplied by Dow Corporation; and soft Fujibopolishing pad supplied by Fujibo, were used for CMP process.

TEOS oxide films by Chemical Vapor Deposition (CVD) usingtetraethylorthosilicate as the precursor

HDP oxide films made by high density plasma (HDP) technique

SiN films—Silicon nitride films

Parameters:

Å: angstrom(s)—a unit of length

BP: back pressure, in psi units

CMP: chemical mechanical planarization=chemical mechanical polishing

CS: carrier speed

DF: Down force: pressure applied during CMP, units psi

min: minute(s)

ml: milliliter(s)

mV: millivolt(s)

psi: pounds per square inch

PS: platen rotational speed of polishing tool, in rpm (revolution(s) perminute)

SF: polishing composition flow, ml/min

Removal Rates and Selectivity

Removal Rate (RR)=(film thickness before polishing−film thickness afterpolishing)/polish time.

Selectivity of TEOS/SiN=TEOS RR/SiN RR; TEOS/poly-Si=TEOS RR/poly-Si RRat same down force (psi)

All percentages are weight percentages unless otherwise indicated.

General Experimental Procedure

In the examples presented below, CMP experiments were run using theprocedures and experimental conditions given below.

The CMP tool that was used in the examples is a Mirra®, manufactured byApplied Materials, 3050 Boweres Avenue, Santa Clara, Calif., 95054.IC1010 pad, supplied by Dow Electronic Chemicals, was used on the platenfor the blanket wafer polishing studies. Pads were broken-in bypolishing twenty-five dummy oxide (deposited by plasma enhanced CVD froma TEOS precursor, PETEOS) wafers

Example 1

Polishing compositions were made as per the compositions listed in table1.

Methyl-isothiazolinone was purchased from Dow Chemicals (USA) undertrade name Neolone M-10.

PL-2 and PL-2L silica abrasive were purchased from Fuso Chemical Company(Tokyo, Japan).

Particle size as measured by dynamic light scattering was approximately50 nm.

Ceria coated silica particles were manufactured by JGC Catalysts andChemicals Ltd (16th Floor, Solid Square East Tower, 580 Horikawa-cho,Saiwai-ku, Kawasaki City, Kanagawa 212-0013 JAPAN).

TABLE 1 Compositions Composition# 1 2 3 4 5 Methyl- 0.05 0.05 0.015 0.050.05 isothiazolinone (wt. %) Fuso PL-2 1 1 1 Silica particles (wt. %)Ceria coated — — 0.3 0.3 silica particles (wt. %) Ammonium 0.1 0.1 0.10.1 0.2 Polyacrylate (wt. %) Water balance balance balance balancebalance pH 5 6 5 5 5

Wafers were polished at 4 psi downforce and 85 RPM table speed.

Table 2 summarized removal rate data on various films with polishingcompositions shown in table 1.

TABLE 2 Removal Rates Poly-Si TEOS SiN Poly-Si/TEOS Poly-Si/SiN removalremoval removal removal removal rate rate rate rare rate ({dot over(A)}/min) ({dot over (A)}/min) ({dot over (A)}/min) Selectivityselectivity 1 1451 43 11 44 132 2 1952 1 28 1952 70 3 1274 33 12 39 1064 1573 2748 129 0.57 12 5 1626 1915 128 0.85 13

Comparison of poly-Si rates between composition 1 and composition 2showed the beneficial impact of increasing pH resulted in the increasedpoly-Si removal rates.

Composition 1 comprising higher methyl-isothialozinone concentration(0.05 wt. %) showed higher removal rate compared to composition 3comprising only 0.015 wt. % methyl-isothialozinone concentration,demonstrating that methyl-isothialozinone acts as a booster of thepoly-Si removal rates.

Compositions comprising ceria coated silica particles andmethyl-isothialozinone show high removal rates of both poly-Si and TEOSfilms. By suitably choosing ammonium polyacrylate concentration, TEOSrate can be modulated to provide desired removal rate selectivity.

Example 2

Polishing compositions were made as per the compositions listed in table3. The formulations used calcined ceria particles as abrasives.

TABLE 3 Compositions Composition# 6 (Comparative) 7 8 Methyl- 0 0.010.05 isothiazolinone (wt. %) Calcined Ceria 0.5 0.5 0.5 particles (wt.%) Ammonium 0.077 0.077 0.077 Polyacrylate ((wt. %) Water balancebalance balance pH 5.2 5.2 5.2

Wafers were polished at 4.7 psi downforce and 87 RPM table speed. Table4 summarizes the removal rate data.

TABLE 4 Removal Rate Poly-Si TEOS Poly-Si/TEOS removal removal removalrare rate ({dot over (A)}/min) rate ({dot over (A)}/min) Selectivity 6272 2139 0.127 (Comparative) 7 1617 1838 0.88 8 1824 1766 1.03

Comparative Composition 6 did not contain methyl isothiazolinonecompound giving very low poly-Si removal rate but high TEOS removalrate, resulting in a selectivity of Poly-Si/TEOS with 0.127.

As evident from the data, Compositions 7 and 8 contained methylisothiazolinone compound showing very high poly-Si removal rate.Compositions 7 and 8 also achieved 1:1 removal rate selectivity betweenpoly-Si and TEOS films which may be desired for certain applications

Example 3

Compositions 9-12 were made comprising 1 wt. % Fuso PL2 particles, 500ppm methyl isothiazolinone, 0.2 wt. % ammonium polyacrylate (Molecularweight 1000-5000) and water.

TABLE 5 Removal Rate Poly-Si TEOS SiN removal removal removalComposition pH rate ({dot over (A)}/min) rate ({dot over (A)}/min) rate({dot over (A)}/min) 9 6 2046 40 32 10 7 2258 15 31 11 8 2423 13 25 1210 3447 20 33

pH of these formulations was adjusted using ammonium hydroxide to values6, 7, 8 and 10 respectively.

Table 5 summarizes the polishing data obtained at 4 psi and 85 RPM.

As evident from table 5, increasing the pH increases the poly-Si ratewithout adversely affecting TEOS and SiN removal rates. Thus, theremoval rate selectivity between poly-Si and TEOS or SiN increases aswell.

Example 4

Composition 13 was made comprising 1 wt. % aluminum containing silicaparticles with 30 nm particle size, 0.2 wt. % ammonium polyacrylate(molecular weight 1000-5000) and 0.05 wt. % methyl isothozolinone, withpH of 5.

Removal rates of Poly-Si, TEOS and SiN at 4 psi downforce and 85 RPMwere 1870 Å/min, 29 Å/min and 33 Å/min respectively.

Composition comprising aluminum containing silica particles andmethyl-isothialozinone showed high removal rate of poly-Si and lowremoval rates of TEOS or SIN films.

Example 5

Composition 14 was made comprising 1 wt. % Fuso PL2 silica particleswith 30 nm particle size, 0.05 wt. % methyl isothozolinone and waterwith pH adjusted to pH of 5.

Removal rates of Poly-Si, TEOS and SiN at 4.5 psi downforce and 85 RPMwere 2363 Å/min, 34 Å/min and 23 Å/min respectively.

This shows that methyl isothiazolinone addition by itself to theabrasive particles results in high poly-Si removal rates. Thecomposition has low removal rates of TEOS or SIN films.

Example 6

Compositions were made comprising combination of ceria containingabrasive particles (Ceria coated silica particles) and silica particlesas described in table 6.

Ceria coated silica particles were manufactured by JGC Catalysts andChemicals Ltd (16th Floor, Solid Square East Tower, 580 Horikawa-cho,Saiwai-ku, Kawasaki City, Kanagawa 212-0013 JAPAN).

TABLE 6 Compositions Composition# 15 16 17 Methyl- 0.05 0.05 0.015isothiazolinone (wt. %) Fuso PL-2L 0 0.5 1 Silica particles (wt. %)Ceria coated 0.1 0.1 0.1 silica particles (wt. %) Ammonium 0.05 0.050.05 Polyacrylate (wt. %) Water balance balance balance pH 6 6 6

Removal rates obtained with poly-Si, TEOS and SiN films at 4 psidownforce and 85 RPM table speed were summarized in table 7

As shown in example 15, ceria containing abrasive particles (Ceriacoated silica particles) provided high silicon oxide removal ratesrelative to poly-Si removal rates.

TABLE 7 Removal Rate Poly-Si TEOS SiN Poly-Si/TEOS Poly-Si/SiN removalremoval removal removal removal rate rate rate rare rate ({dot over(A)}/min) ({dot over (A)}/min) ({dot over (A)}/min) Selectivityselectivity 15 1079 1823 61 0.59 17.68 16 2969 1621 57 1.83 52.08 173027 1175 47 2.57 64.4

However, with addition of silica particles (PL-2L silica particles fromFuso Ltd), there was substantial boost in poly-Si removal rates,resulting in poly-Si to TEOS removal rate selectivity as high as 2.57.Combination of ceria containing particles (Ceria coated silicaparticles) and silica particles also provided significant improvement inpoly-Si to silicon nitride removal rate selectivity.

Compositions in working examples have shown a remarkable removal rateselectivity between elemental silicon and silicon oxide or SiN rangingfrom 0.1 to 110. This tunable selectivity is very useful in thesemiconductor process.

The foregoing examples and description of the embodiments should betaken as illustrating, rather than as limiting the present invention asdefined by the claims. As will be readily appreciated, numerousvariations and combinations of the features set forth above can beutilized without departing from the present invention as set forth inthe claims. Such variations are intended to be included within the scopeof the following claims.

1. A polishing composition comprising: abrasive particles ranging from0.01 wt. % to 15 wt. %; a compound to enhance removal rate of filmscomprising elemental silicon ranging from 0.001 wt. % to 0.5 wt. %;liquid carrier; and pH of the polishing composition is between 2 and 12;wherein the abrasive particles are selected from the group consisting offumed silica, colloidal silica, fumed alumina, colloidal alumina, ceriumoxide, ceria-silica composite particles, titanium dioxide, zirconiumoxide, polystyrene, polymethyl methacrylate, mica, hydrated aluminumsilicate, and combinations thereof; and the compound to enhance removalrate of films comprising elemental silicon is selected from the groupconsisting of (i) heterocycle carbon compound comprising sulfur ornitrogen or both sulfur and nitrogen as heteroatoms and a carbonyl groupattached to the ring structure; (ii) heterocycle carbon compoundcomprising sulfur or nitrogen or both sulfur and nitrogen asheteroatoms; (iii) an aldehyde or a ketone compound; and combinationsthereof.
 2. The polishing composition of claim 1, wherein the compoundto enhance removal rate of films comprising elemental silicon isselected from the group consisting of isothiazolinone and derivatives,thiazolinone and derivatives.
 3. The polishing composition of claim 2,wherein the isothiazolinone and derivative is selected from the groupconsisting of methylisothiazolinone (MIT), chloromethylisothiazolinone(CMIT), benzisothiazolinone (BIT), octylisothiazolinone (OIT),dichlorooctylisothiazolinone (DCOIT), butylbenzisothiazolinone (BBIT),and combinations thereof; and the thiazolinone and derivative isselected from the group consisting of 2-Benzothiazol-1,1,3-trione(Saccharin), N-methyl 2-Benzothiazolinone, thiazolinone, andcombinations thereof.
 4. The polishing composition of claim 1, whereinthe compound to enhance removal rate of films comprising elementalsilicon is selected from the group consisting of imidazolidine andderivatives, pyrozolidine and derivatives, imidazole and derivatives,pyrazole and derivatives, thiazole and derivatives, isothiazole andderivatives, thiazolidine and derivatives, isothiazolidine andderivatives, dithiolane and derivatives, triazole and derivatives,tetrazole and derivatives, thiadiazole and derivatives, and combinationsthereof; or is selected from the group consisting of acetone,benzophenone, acetophenone, acetylacetone, butanol, 3-hydroxybutanal,p-nitrobenzaldehyde, cinnamaldehyde, vanillin, and combinations thereof.5. The polishing composition of claim 1, wherein the liquid carrier iswater; and the pH of the polishing composition is between 4 and
 10. 6.The polishing composition of claim 5, wherein, the abrasive particlescomprise cerium oxide containing particles and colloidal silicaparticles.
 7. The polishing composition of claim 1, further comprisesfrom 0.1 ppm to 0.5 wt. % of a compound selected from a polymer orcopolymer comprising acrylic acid groups with molecular weight rangingbetween 500 and 100,000, a compound having a functional group selectedfrom the group consisting of organic carboxylic acids, amino acids,amidocarboxylic acids, N-acylamino acids, and their salts thereof;organic sulfonic acids and salts thereof; organic phosphonic acids andsalts thereof; polymeric carboxylic acids and salts thereof; polymericsulfonic acids and salts thereof; polymeric phosphonic acids and saltsthereof; arylamines, aminoalcohols, aliphatic amines, heterocyclicamines, hydroxamic acids, substituted phenols, sulfonamides, thiols,polyols having hydroxyl groups, and combinations thereof.
 8. Thepolishing composition of claim 1, further comprises a polymer orcopolymer comprising acrylic acid groups with molecular weight rangingbetween 500 and 100,000.
 9. The polishing composition of claim 7,wherein the polymer or copolymer comprising acrylic acid groups isammonium polyacrylate.
 10. The polishing composition of claim 1, furthercomprises at least one of (1) an additive having a functional groupselected from the group consisting of organic carboxylic acids and saltsthereof, amino acids and salts thereof, amidocarboxylic acids and saltsthereof, N-acylamino acids and salts thereof, organic sulfonic acids andsalts thereof; organic phosphonic acids and salts thereof; polymericcarboxylic acids and salts thereof; polymeric sulfonic acids and saltsthereof; polymeric phosphonic acids and salts thereof; arylamines,aminoalcohols, aliphatic amines, heterocyclic amines, hydroxamic acids,substituted phenols, sulfonamides, thiols, polyols having hydroxylgroups, and combinations thereof; wherein the additive ranges from 0.1ppm to 0.5 wt. %; (2) a pH adjusting agent selected from the groupconsisting of sodium hydroxide, cesium hydroxide, potassium hydroxide,cesium hydroxide, ammonium hydroxide, quaternary organic ammoniumhydroxide (e.g. tetramethylammonium hydroxide), salts of polyacrylicacid, citric acid, acetic acid, carbonic acid, bicine, tricine, Tris,4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid,N-cyclohexyl-3-aminopropanesulfonic acid,3-(N-morpholino)propanesulfonic acid, andpiperazine-N,N-bis(2-ethanesulfonic acid), and mixtures thereof; whereinthe pH adjusting agent ranges from 0.0005% to 1 wt. %; (3) a surfactantselected from the group consisting of a). Non-ionic surface wettingagents; b). Anionic surface wetting agents; c). Cationic surface wettingagents; d). ampholytic surface wetting agents; and mixtures thereof;wherein the surfactant ranges from 0.001 wt. % to about 1 wt. %; (4)biological growth inhibitors or preservatives to prevent bacterial andfungal growth during storage.
 11. A polishing method for chemicalmechanical planarization of a semiconductor substrate comprising atleast one surface containing elemental silicon, comprising the steps of:contacting the at least one surface containing elemental silicon with apolishing pad; delivering a polishing composition to the at least onesurface containing elemental silicon; wherein the polishing compositioncomprising: abrasive particles ranging from 0.01 wt. % to 15 wt. %; acompound to enhance removal rate of films comprising elemental siliconranging from 0.001 wt. % to 0.5 wt. %; and liquid carrier; and pH of thepolishing composition is between 2 and 12; wherein the abrasiveparticles are selected from the group consisting of fumed silica,colloidal silica, fumed alumina, colloidal alumina, cerium oxide,ceria-silica composite particles, titanium dioxide, zirconium oxide,polystyrene, polymethyl methacrylate, mica, hydrated aluminum silicate,and combinations thereof; and the compound to enhance removal rate offilms comprising elemental silicon is selected from the group consistingof isothiazolinone and derivatives, thiazolinone and derivatives,imidazolidine and derivatives, pyrozolidine and derivatives, imidazoleand derivatives, pyrazole and derivatives, thiazole and derivatives,isothiazole and derivatives, thiazolidine and derivatives,isothiazolidine and derivatives, dithiolane and derivatives, triazoleand derivatives, tetrazole and derivatives, thiadiazole and derivatives,acetone, benzophenone, acetophenone, acetylacetone, butanol,3-hydroxybutanal, p-nitrobenzenzaaldehyde, cinnamaldehyde, vanillin, andcombinations thereof; and polishing the at least one surface containingelemental silicon with the polishing composition.
 12. The polishingmethod of claim 11, wherein the compound to enhance removal rate offilms comprising elemental silicon is selected from the group consistingof (i) isothiazolinone and derivative selected from the group consistingof methylisothiazolinone (MIT), chloromethylisothiazolinone (OMIT),benzisothiazolinone (BIT), octylisothiazolinone (OIT),dichlorooctylisothiazolinone (DCOIT), butylbenzisothiazolinone (BBIT),and combinations thereof; and (ii) thiazolinone and derivative selectedfrom the group consisting of 2-Benzothiazol-1,1,3-trione (Saccharin),N-methyl 2-Benzothiazolinone, thiazolinone, and combinations thereof;and combinations thereof.
 13. The polishing method of claim 11, whereinthe polishing composition comprises methylisothiazolinone (MIT); theliquid carrier is water; and the pH of the polishing composition isbetween 4 and
 10. 14. The polishing method of claim 11, wherein thesemiconductor substrate further comprises at least one surfacecontaining silicon oxide, silicon nitride or combinations thereof; andthe polishing composition further comprises from 0.1 ppm to 0.5 wt. % of(i) a polyacrylic acid or its salts with molecular weight rangingbetween 500 and 100,000; (ii) an additive having a functional groupselected from the group consisting of organic carboxylic acids and saltsthereof, amino acids and salts thereof, amidocarboxylic acids and saltsthereof, N-acylamino acids and salts thereof, organic sulfonic acids andsalts thereof; organic phosphonic acids and salts thereof; polymericcarboxylic acids and salts thereof; polymeric sulfonic acids and saltsthereof; polymeric phosphonic acids and salts thereof; arylamines,aminoalcohols, aliphatic amines, heterocyclic amines, hydroxamic acids,substituted phenols, sulfonamides, thiols, polyols having hydroxylgroups, and combinations thereof; or combinations of (i) and (ii);wherein removal rate selectivity between elemental silicon and siliconoxide or silicon nitride is tunable between 0.1 to
 110. 15. Thepolishing method of claim 13, wherein the polishing compositioncomprises methylisothiazolinone (MIT); ammonium polyacrylate withmolecular weight ranging between 500 and 100,000; the liquid carrier iswater; and the pH of the polishing composition is between 4 and
 10. 16.The polishing method of claim 11, wherein the polishing compositionfurther comprises at least one of (1) a pH adjusting agent selected fromthe group consisting of sodium hydroxide, cesium hydroxide, potassiumhydroxide, cesium hydroxide, ammonium hydroxide, quaternary organicammonium hydroxide (e.g. tetramethylammonium hydroxide), salts ofpolyacrylic acid, citric acid, acetic acid, carbonic acid, bicine,tricine, Tris, 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid,N-cyclohexyl-3-aminopropanesulfonic acid,3-(N-morpholino)propanesulfonic acid, andpiperazine-N,N-bis(2-ethanesulfonic acid), and mixtures thereof; whereinthe pH adjusting agent ranges from 0.0005% to 1 wt. %; (2) a surfactantselected from the group consisting of a). Non-ionic surface wettingagents; b). Anionic surface wetting agents; c). Cationic surface wettingagents; d). ampholytic surface wetting agents; and mixtures thereof;wherein the surfactant ranges from 0.001 wt. % to about 1 wt. %; and (3)biological growth inhibitors or preservatives to prevent bacterial andfungal growth during storage.
 17. A system for chemical mechanicalplanarization a semiconductor substrate comprising at least one surfacecontaining elemental silicon, comprising: the semiconductor substrate; apolishing pad; and a polishing composition comprising: abrasiveparticles ranging from 0.01 wt. % to 15 wt. %; a compound to enhanceremoval rate of films comprising elemental silicon ranging from 0.001wt. % to 0.5 wt. %; and liquid carrier; and pH of the polishingcomposition is between 2 and 12; wherein the abrasive particles areselected from the group consisting of fumed silica, colloidal silica,fumed alumina, colloidal alumina, cerium oxide, ceria-silica compositeparticles, titanium dioxide, zirconium oxide, polystyrene, polymethylmethacrylate, mica, hydrated aluminum silicate, and combinationsthereof; and the compound to enhance removal rate of films comprisingelemental silicon is selected from a group consisting of isothiazolinoneand derivatives, thiazolinone and derivatives, imidazolidine andderivatives, pyrozolidine and derivatives, imidazole and derivatives,pyrazole and derivatives, thiazole and derivatives, isothiazole andderivatives, thiazolidine and derivatives, isothiazolidine andderivatives, dithiolane and derivatives, triazole and derivatives,tetrazole and derivatives, thiadiazole and derivatives; acetone,benzophenone, acetophenone, acetylacetone, butanol, 3-hydroxybutanal,p-nitrobenzenzaaldehyde, cinnamaldehyde, vanillin, and combinationsthereof; wherein the semiconductor substrate is in contact with thepolishing composition and the pad.
 18. The system of claim 17, whereinthe compound to enhance removal rate of films comprising elementalsilicon is selected from a group consisting of (i) isothiazolinone andderivative selected from the group consisting of methylisothiazolinone(MIT), chloromethylisothiazolinone (CMIT), benzisothiazolinone (BIT),octylisothiazolinone (OIT), dichlorooctylisothiazolinone (DCOIT),butylbenzisothiazolinone (BBIT), and combinations thereof; and (ii)thiazolinone and derivative selected from the group consisting of2-Benzothiazol-1,1,3-trione (Saccharin), N-methyl 2-Benzothiazolinone,thiazolinone, and combinations thereof; and combinations thereof. 19.The system of claim 17, wherein the polishing composition comprisesmethylisothiazolinone (MIT); the liquid carrier is water; and the pH ofthe polishing composition is between 4 and
 10. 20. The system of claim17, wherein the semiconductor substrate further comprises at least onesurface containing silicon oxide, silicon nitride or combinationsthereof; and the polishing composition further comprises from 0.1 ppm to0.5 wt. % of (i) a polyacrylic acid or its salts with molecular weightranging between 500 and 100,000; (ii) an additive having a functionalgroup selected from the group consisting of organic carboxylic acids andsalts thereof, amino acids and salts thereof, amidocarboxylic acids andsalts thereof, N-acylamino acids and salts thereof, organic sulfonicacids and salts thereof; organic phosphonic acids and salts thereof;polymeric carboxylic acids and salts thereof; polymeric sulfonic acidsand salts thereof; polymeric phosphonic acids and salts thereof;arylamines, aminoalcohols, aliphatic amines, heterocyclic amines,hydroxamic acids, substituted phenols, sulfonamides, thiols, polyolshaving hydroxyl groups, and combinations thereof; or combinations of (i)and (ii); wherein the system provides a tunable removal rate selectivitybetween elemental silicon and silicon oxide or silicon nitride between0.1 to
 110. 21. The system of claim 20, wherein the polishingcomposition comprises methylisothiazolinone (MIT); ammonium polyacrylatewith molecular weight ranging between 500 and 100,000; the liquidcarrier is water; and the pH of the polishing composition is between 4and
 10. 22. The system of claim 17, wherein the polishing compositionfurther comprises at least one of (1) a pH adjusting agent selected fromthe group consisting of sodium hydroxide, cesium hydroxide, potassiumhydroxide, cesium hydroxide, ammonium hydroxide, quaternary organicammonium hydroxide (e.g. tetramethylammonium hydroxide), salts ofpolyacrylic acid, citric acid, acetic acid, carbonic acid, bicine,tricine, Tris, 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid,N-cyclohexyl-3-aminopropanesulfonic acid,3-(N-morpholino)propanesulfonic acid, andpiperazine-N,N-bis(2-ethanesulfonic acid), and mixtures thereof; whereinthe pH adjusting agent ranges from 0.0005% to 1 wt. %; (2) a surfactantselected from the group consisting of a). Non-ionic surface wettingagents; b). Anionic surface wetting agents; c). Cationic surface wettingagents; d). ampholytic surface wetting agents; and mixtures thereof;wherein the surfactant ranges from 0.001 wt. % to about 1 wt. %; and (3)biological growth inhibitors or preservatives to prevent bacterial andfungal growth during storage.